Idle Air Control (IAC) Motor

Fig 10 MAP And Throttle Position Sensor Location - Typical:

DESCRIPTION
The throttle body has an air control passage that provides air for the engine at idle (the throttle plate is closed). The Idle Air Control (IAC) motor pintle protrudes into the air control passage and regulates air flow through it.

OPERATION
Based on various sensor inputs, the powertrain control module (PCM) adjusts engine idle speed by moving the IAC motor pintle in and out of the air control passage. The IAC motor is positioned when the ignition key is turned to the On position.

A (factory adjusted) set screw is used to mechanically limit the position of the throttle body throttle plate. Never attempt to adjust the engine idle speed using this screw. All idle speed functions are controlled by the PCM.

CIRCUIT OPERATION
The Powertrain Control Module (PCM) operates the Idle Air Control motor through four circuits; K39, K40, K59, and K60. Each circuit connects to separate cavities in the PCM connector.
- Circuit K39 connects to cavity A19 of the PCM connector.
- Circuit K40 connects to cavity A11 of the PCM connector.
- Circuit K59 connects to cavity A20 of the PCM connector.
- Circuit K60 connects to cavity A10 of the PCM connector.